Utah already has it, I think. Also Amazon (the retailer) has it’s own currency of sorts, which is not such a bad idea as they reach across state and even national boundaries and could function as part of a substitute exchange mechanism. If they could get together with the eBays and other such entities (maybe the states themselves), they could replace a large part of the monetary system, as least as far as buying/selling/trading is concerned. If the dollar does collapse, the market may find ways to adapt.